Large scale data centers are increasingly used for a wide variety of tasks associated with applications such as electronic mail and Web browsing. For example, software as a service (SaaS) includes Web-based e-mail services (e.g., the MICROSOFT® HOTMAIL® e-mail service) where a vendor typically hosts all of the program logic and data and provides end users with access to this data over the public Internet. Such a service may rely on a distributed application and a large amount of data, which may be stored in more than one data center. A single data center can house thousands of individual storage devices, usually in the form of rack mounted computers, which may be servers. Many now refer to large data centers as “server farms”. Resource management is an important aspect of data center operation. Various exemplary techniques are described herein for data center management and operation.